Focusing device for lanterns



Dec 30, 1924,

f C. H. KELSEA FOCUSING DEVICE FOR LANTERNS Filed Deo. 3, 1921 34luv Patented Dec. 30, 1924.

PATENTv OFFICE.

CLARENCE H. KELSEA, OF BELMONT, MASSACHUSETTS, ASSIGNOR TO PETER GRAY & SONS INC., OF CAMBRIDGE, MASSACHUSETTS, A CORPORATO'N 0F MASSACHUSETTS.

FOCUSING DEVICE FOR LANTERNS.

Application led December 3,1921. Serial No. 519,632.

To all whom it may concern:

Be it "known that I, CLARENCE H. KELSEA, a citizen of the United States, residing in Belmont, in the county of Middlesex and Statek of Massachusetts, have invented an Improvement in Focusing Devices for Lanterns, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to an illuminating apparatus of that character in which a source of light is adjustable with relation to a reflector, and is herein shown as embodied in a lantern provided with an incandescent lamp and especially adapted among other uses tobe employed as a signal lantern on railways, vessels and the like. j

The invention has for its object to provide a simple', eiicient and inexpensive device for adjusting the electric lamp or otherv source of light with relation to the reflector `to obtain the desired beam of light projected by the refiector.'

Thev invention also has for its objectvto provide an adjusting device, with which single or double contact sockets for the electric lamp may be used as desired, and

which enables the electric circuit for theV lamp to be independent of the metal casing of .the lantern, thereby avoiding4 the inclusion in the lamp circuit of the metal casing and the resistance oli'ered thereby, to-

gether with the consequent heating of the.

casing with its attendant objectionable features.

To this end, the adjusting device 1s provided with a sliding member which supports the socketfor the incandescent lamp, and` with a rotatable member which supports the sliding member andv upon which the latter slides to effect radial adjustment of the lamp with relation to the axis of the re-' flector.

The rotatable member is preferably made in two parts and of insulating material and cooperates with a supporting member, which may and preferably will be a part of the metal housing for the reflector.

These and other features of the invention will be pointed out in the claims at the end of this specification.

Fig. 1 is a longitudinal vertical section of a signal lantern embodying this invention.

Fig. 2, an enlarged detail of the adjusting device shown in Fig. 1 with the parts in a position substantially Vat right angles to that shown in Fig. 1.

Fig. 3, an end elevation looking toward the left in Fig. 2. j'

Fig. 4," a section on the line 4 4, Fig. 2, looking toward the right.

Figs. 5 and 6, views like Fig. 3 with the sliding member in eXtreme adjusted positionson opposite sides of the center position shown in Fig. 3, and

Fig. 7, a detail in elevation showing the engagement of the sliding member with the rotatable member. i

Referring to the drawing, a represents the metal casing of a signal lantern of known construction and provided at its front end with the usual cover glass b, and at its rear end with the `sliding door or cover plate c. I j

The casing a contains Within it the reflector d and the metal housing e therefor, which is suitably supported by the casing a and is provided with a rear wall or back plate f. The refiector d is secured to its housing e` b v the metal clips 10, and has cooperating with it an incandescent lamp 12 whose plug member 13 is extended through an opening 14. in the rear end of the reflector and into a socket member l5, which may be of the double contact type, but which is preferably of the single contact type, as herein represented.

The socket member 15 is provided with external screw threads 16 which engage an internally threaded metal bushing 17, through which the socket member 15 is extended.

The metal bushing 17 and the socket member 15 are supported by onemember of an adjusting device, which member is represented as a metal disk 20 having a central h ole through which the front reduced por tion of the bushing 17 projects and against which a shoulder 22 on `the bushing bears and is soldered thereto. The metal disk 2O 1s mounted to slide radially on a rotatable member' of the adjusting device, and said rotatable member is herein shown as composedof two circular disks 24, 25 of insulatf ing material, which are secured together and In the yresent instance the disk 24 is'provided with a hub 26 which is extended through a circular hole in the back plate f, and whose center-is concentricrxvith the horif. zontal axis of thereflector (l, and the disk 25 is provided with an annular` fl'ange 27, which extends over the hub 26 and engages the plate]c on the side opposite to the disk 24. The disks 24, 25 mav be secured in fixed relationto the plate f .by bolts 30 located substantially diametrically opposite and eX-' tended through the sliding disk 20, the disks .25, 24, and a metal disk 31 on the outside of which project into a guidevvay or diametrical slot 35 in the outer surface of the disk 25.

Provision is made for permitting the bushing 17 and the lam socket' 15 to be moved with the sliding disk 20, and to` this end the disks 24, 25 are provided with elongated slots 36, see Figs. 1 and 4, which coincide and practically form one slot through which the bushing17 extends. j

Theslots 36 extend in the same direction as4 the slots`32 in the slidable disk 20. The boltsl 30 have mounted upon them between the disk 20 and the heads of the bolts, spring Washers 38, which serve to keep the disks 24, 25 connected together so as to be rotated Vas one piece, .after the bolts 30 have been loosened sufficiently to permit the said disks to be turned or rotated in the opening in the plate f. The socket member 15 has mounted on it one connector 40 for the electric circuit in which thev lamp 12 is included, and said socket member also carries a plug 41 of insulating material, through which is ex-` tended a contact member 42, which has attached to it a second connector 43 for said electric circuit. The connector 40 is fitted on to the socket member 15 between vthe bushing 17 and the nut23 thereon.

From the above description it Will be seen that by means of the rotatable adjustable member and the ysliding adjustable member, the lamp 12 may be adjusted radially into any desired position with relation to the horizontal axis of the reflector. and by turning the socket member 15 in its bushing 17, the lamp 12 may be, adjusted longitudinally 'with relation to a vertical plane through the I focal axis of the reflector, and that these adjustments may be made in a minimum time. Furthermore, it will be observed that the members of the adjusting device are accessible to the operator by removing 'the cover plate c.

It will also be observed that the electric circuit of the lamp 12 is from one connector -as 43 through the plugmember 42, lfilament of the lamp 12, socket member 15 and con-l nector 40, fand does not include the housing f, e, for the reflector d or the casing a, and as a'result, resistancedue to said casing and housing, with corresponding` consumption `of, current is avoided, and heatingof said parts is also avoided, which enables the lantern to be handled Without objection on the,`

part of the operator, and therefore enables.

the lamp to be adjusted While inuse With` out inconvenience to the operator. It will also be observed, that the desired adjustment may be 'effected in a minimum time. e

So also the arts of the adjustinl device are simple an inexpensive, and W en the lamp has been adjusted, it may be firmly se Y e cured, wherebythe lamp socket is to all intentsv and .purposes secured against movement, thereby avoiding accidental derangementof the lamp adjustment.

One embodiment of the invention is herein shown, but -it is not desired tojlimit the member slides. means for supporting said. rotatable member, and means for securing said rotatable member infixed relation to. its supportingmeans and said sliding mem.

ber in fixed relation to said rotatable member. a Y l v i 2. In an illuminatingapparatus, in combination, areflector, an incandescent lamp, a socket member for said lamp, and an adjusting device for said lamp, comprising a rotatable member having an elongated slot into which said socket member is extended, and a supporting member for said socket member mounted on said rotatable member toslide thereon in the direction of the length lul) of the slot therein and to rotate'therewith.

3. In an illuminating apparatus, in combmation, an incandescentlamp. a socket member for said lamp, and anadjusting de-` to the axis of said rotatable member and through which said socket `member is extended and in which it is movable in the Y direction of the length of said slot, and a supporting member :for said socket member l. metal disk supporting said light source and mounted on said insulating disk to slide thereon radially with relation to the axis of said 4disk and in the direction of the length of said slot, and means for securing said metal disk in its adjusted position on said insulatingv disk.

vIn testimony whereof, I have signed my name to this speciication.

CLARENCE H. KELSEA. 

